Hollow-fiber ultrafiltration for the concentration and simultaneous recovery of multiple pathogens in contaminated
Hee-Yeon Kim1, Hyeun-Jin Park, Gwangpyo Ko
1Department of Environmental Health and Institute of Health and Environment, School of Public Health, Seoul National University, Seoul, Korea.
Abstract:
We investigated the possibility of using hollow-fiber ultrafiltration (HUF) for the simultaneous recovery of multiple microorganisms in food samples. MS2 bacteriophage, E. coli, Bacillus subtilis spores, and murine norovirus (MNV) were each inoculated into 5 liters of either distilled water (DW) or glycine elution buffer and then concentrated using hollow-fiber polysulfone ultrafilters. The resulting concentrates were further analyzed by either cultivation or TaqMan real-time reverse transcription PCR assay. The overall average recovery rates were 7.1% in DW and 17.1% in glycine elution buffer. When the virus, vegetative bacteria, and bacterial spores were simultaneously inoculated into DW, glycine, or Tris-HCl elution buffers, on average 16.8% of inoculated microorganisms were recovered by HUF. The addition of 3% beef extract blocking buffer to HUF increased the total recovery rate to 46.1%, with incremental recovery rates increasing sharply for B. subtilis spores and MNV. Use of HUF resulted in E. coli recovery rates of 68.0% on lettuce and 66.2% on ham and MNV recovery rates of 1.5% on lettuce and 5.8% on ham. Our study demonstrates that HUF can be effective at simultaneously recovering and concentrating diverse bacterial and viral pathogens from foods.
Insights
Hollow-fiber ultrafiltration (HUF) effectively recovers diverse foodborne pathogens. Adding beef extract blocking buffer significantly boosts recovery rates for viruses and bacterial spores.
Area of Science:
- Food safety microbiology
- Water and foodborne pathogen detection
- Filtration and concentration techniques
Background:
- Accurate detection of foodborne pathogens is crucial for public health.
- Traditional methods often require extensive sample processing for pathogen recovery.
- Simultaneous recovery of diverse microorganisms (viruses, bacteria, spores) presents a challenge.
Purpose of the Study:
- To evaluate hollow-fiber ultrafiltration (HUF) for simultaneous recovery of multiple foodborne microorganisms.
- To assess the impact of different elution buffers and blocking agents on recovery efficiency.
- To determine HUF's effectiveness in concentrating pathogens from various food matrices.
Main Methods:
- Inoculation of MS2 bacteriophage, E. coli, Bacillus subtilis spores, and murine norovirus (MNV) into distilled water or elution buffers.
- Concentration of microorganisms using hollow-fiber polysulfone ultrafilters.
- Analysis of concentrates via cultivation and TaqMan real-time reverse transcription PCR.
- Testing the effect of beef extract blocking buffer on recovery rates.
- Application of HUF for pathogen recovery from lettuce and ham samples.
Main Results:
- Average recovery rates were 7.1% in distilled water and 17.1% in glycine elution buffer.
- Simultaneous recovery of virus, bacteria, and spores averaged 16.8% without blocking buffer.
- Addition of 3% beef extract blocking buffer increased overall recovery to 46.1%.
- Significant increases in recovery rates for B. subtilis spores and MNV were observed with blocking buffer.
- HUF achieved E. coli recovery rates of ~67% on lettuce and ham, and MNV recovery rates of ~3.6% on these foods.
Conclusions:
- Hollow-fiber ultrafiltration is a viable method for simultaneous recovery of diverse bacterial and viral pathogens from food samples.
- Optimizing elution buffers and using blocking agents like beef extract can substantially improve HUF efficiency.
- HUF offers a promising approach for concentrating pathogens, aiding in sensitive detection for food safety.
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